Arrangement for slat screens for solar protection

ABSTRACT

Arrangement of slat screens for solar protection of the type having a number of slats (24;44) supported by girders (5) or the like, which slats are placed apart from each other and together form a solar screen. The girders (5) have slat holders (16) with projections (21) with surfaces which face away from each other. These surfaces slope in such a way relative to each other that they form together an entry portion (22) which on the inside is terminated by a groove (23) in each projection. The slats (24) are provided with a fixture (28,29) which has two opposing flanges (28) with outer hook-shaped projections (29) facing each other. The distance between the flanges is so chosen that the hook-shaped projections can be guided onto the widened out entry portion (22) so that during the bending of the flanges they are made to pass the widest part of the entry portion which is wider than the distance between the hook-shaped projections. After passing the entry portion the hook-shaped projections (29) snap down into the said grooves (23) by means of which the slat is held in positon 
     Furthermore it is intended that the slats (44) should be provided with a longitudinal tubular section (64) arranged to be traversed by a flow of a fluid, by means of which the heat formed as result of the solar radiation against the slat can be removed in that the slat is connected to a piping system for the fluid.

TECHNICAL FIELD

The present invention relates to an arrangement of slat screens forsolar protection of the type provided with girders having slat holderswhich carry slats which are located at a distance from each other andwhich together form screens which intercept the sun's rays in apredetermined angular zone.

BACKGROUND

The method is known of designing screens which are intended to bemounted on facades and to prevent solar irradiation through the facadewindows, at least for certain angles of incidence of the sun's rays. Theknown type of such sun screens to which the present invention relates isprovided with a number of slats which are supported at intervals bygirders and which together form an obstacle to the rays of the sunwithin the predetermined angular zone.

TECHNICAL PROBLEM

It is obviously desirable that such a sun screen, whilst satisfying thefunctional need imposed and complying with the necessary strengthrequirements, should be capable of being produced at an acceptable costand in such a manner that to the largest possible extent standardisedcomponents can be employed for constructing the different types of sunscreen required for different installation purposes.

THE SOLUTION

On the sun screen the supporting girders have projections on the slatholders, with surfaces which are directed away from each other and whichslope in such a way in relation to each other that they form an entryportion, which opens out, and which is terminated inwards by means ofgrooves. Each of the slats includes a fixture provided with twooppositely-facing flanges with outer hook-projections. The distancebetween the flanges is so chosen that the hook-projections can beoffered up to the entry portion and, during the bending of the flanges,be made to pass the widest part of the entry portion so that thehook-shaped projections will snap down into the grooves so that the slatis held in place by this means. Furthermore it is intended that theslats should be provided with a longitudinal tubular section designed tobe traversed by a fluid, by means of which heat formed in the event ofsolar radiation against the slats can be dissipated because the slatsare connected to a piping system for the fluid.

ADVANTAGES

By means of the invention a sun screen is provided which enables manytypes and sizes to be constructed using a few standard components andwith the minimum possible amount of erection work. Furthermore the sunscreen can be designed for a further purpose apart from solar screening,namely the interception of solar energy.

BRIEF DESCRIPTION OF DRAWINGS

The invention is shown on the appended drawings.

FIG. 1 shows in detail a solar screen in an initial embodiment in sideview;

FIG. 2 shows a section appertaining to the solar screen;

FIGS. 3, 4 and 5 illustrate three further types of solar screens whichare made up of essentially the same components as that illustrated inFIG. 1;

FIG. 6 illustrates a slat of a design different from the slats shown inFIG. 1, with a view of a section along the line VI--VI in FIG. 7, whilst

FIG. 7 shows an end view along the line VII--VII of two of the slats inaccordance with FIG. 6.

BEST MODE OF CARRYING OUT THE INVENTION

In FIG. 1 the dash-dotted lines illustrate a house facade 1. Twofixtures 2 and 3 are mounted on the latter. Fixture 2 supports by meansof bolts 4 a girder 5. By means of a bolt 6 the fixture 3 supports astay 7 which by means of bolts 8 holds the girder 5 in the horizontalposition. The stay 7 consists of a T-section with a web 9 which is cutoff above the flange 10 of the section at the ends so as to formtongues, through which extend holes for the bolts 6 and 8 and againstthe outsides of which the heads of the bolts can rest.

The profile of the girder 5, as shown in FIG. 2, has a groove 11 whichis open at the top inside flanges 12 which extend inwards together witha section 13 which is a closed cross section. This section 13 has alower face 14 with two shallow grooves 15. The flanges 12 of groove 11are employed for holding the bolts 8 which, by means of nuts grips thestay 7. The fixture 2 is also attached to the flanges 12. The lower face14 of the lower portion 13 is employed for gripping the holder 16. Thisis done by means of bolts 18 which extend through the holders 16. Thesebolts are of the self-tapping and self-threading type and they are fixedby being introduced whilst being rotated into the drilling indentationsformed by the grooves in the holder and groove 15.

In addition the holders 16 have the flange 19 which is held by means ofthe bolts 18 against flange 20 which is set at an angle to this flange.On this flange two projections 21 are provided having sloping surfaces22 which face away from each other also a groove 23 located furthest intowards flange 20 so as to form hook-shaped end portions. The surfaces22 slope inwards towards each other.

The two projections 21 are employed for holding a slat 24. The slat 24has an extended portion 25 which comprises the actual solar protectionportion together with an end portion 26 which is located obliquely inrespect of the former portion. At its inner end the slat 24 has aportion 27 which is parallel to portion 26 with two flanges 28. Theflanges 28 are terminated by inwardly facing hook portions 29 which fitinto the grooves 23 (see FIG. 6). The flanges 28 are sufficiently long,with the material and the material thickness selected, to provide suchspringiness that the hooks can be introduced along the sloping surfaces22 on the hooks 21 and into the respective grooves 23 into which thehook portions 29 snap downwards and effectively hold the slat firmly inposition. Thus the slats can be attached by means of a simplesnap-action operation. It is usually the slats which are subjected todamage, e.g. by dropping snow, and hence have to be replaced. This caneasily be done by opening up the flanges 29 so that the slat can beremoved from the hooks 21, followed by a new slat being snapped intoposition. Each slat is supported by at least two girders 5 and is keptby these in the horizontal position. Because the slats can slide in thesnap fastening, thermal movements can easily be accommodated. It isappropriate here that each slat be locked into a girder.

As shown in FIG. 1, the outermost holder 16 faces the opposite way tothe others. This is designed to carry a front fitting 31 which also hasflanges 33 with hook portions designed to snap down into the groove 29of the holder. It is best if all components (apart from the fixingcomponents) are made from extruded light metal profiles, which can beprovided with a complicated shape during manufacture.

FIG. 3 illustrates a somewhat modified embodiment. Instead of thefixtures 2 and 3 and the stay 7, here there is a fixture 34 in the formof a U-profile, through the web of which holes extend through whichbolts 35 can extend into the facade wall 1 in order to hold the fixture34. The girder 5 is in turn held against the fixture 34 by two bolts 36which extend through the flanges of the U-shaped girder. In this casethe girder 5 is terminated by a downward-facing portion 37, the side 14of which (FIG. 2) faces outwards, i.e. away from the facade 1. Thisportion can be fixed by bolting or welding to the rest of the girder andhas three holders 16 which support three slats 24. These slats thuscomprise the front of the sun screen and, by adjustment of the length ofportion 37, the front can be given the desired height. By making thefront relatively high in this way the length of the sun screen outwardsfrom the facade can be reduced.

In some cases it can be advantageous to install the sun screen so thatit slopes outward from the facade. This is shown in FIG. 4. Here thegirder 5 is attached in a fixture 38 of the same type as fixture 34.However holes for the attachment bolts 39 for girder 5 are located alonga sloping line so that the girder slopes downwards. The diagram alsoshows how the slats can be attached to the top side of the girder, whichpresupposes that this is turned with the groove 11 facing downward.

FIG. 5 illustrates a further embodiment where the entire sun screen isvertical. Thus the girder 5 extends vertically and is supported by anextra girder 40 with end fixtures 41 and 42 which join it with thefacade 1 and the girder 5. The slats 24 are placed on the outside ofgirder 5 and are fastened as described previously.

The various forms described herein are selected dependent on thelatitude (solar irradiation angle), the desired shading, window heightand distance between dwellings, also the amount to which it is desiredto have the sun screen projecting, together with other factors such asaesthetic factors. The description provided above shows how versatilethe main components of the sun screen are in use.

FIG. 6 illustrates how the sun screen can be adapted to suit a purposeother than its solar screening function. Naturally enough sun screensare erected on facades which are subjected to intense solar radiationand it is known that considerable heating up of the sun screens occursduring sunny periods. The object of the embodiment which will bedescribed now is to utilise the solar heat so that in conjunction withthe arrangement of the sun screens it is possible to obtain a solarinterceptor arrangement at a very restricted extra cost.

FIG. 6 shows a slat 44, the basic shape of which corresponds essentiallywith slat 24. Thus slat 44 has a fixture 45 of the same type as thatdescribed previously, together with an extended portion 46. The extendedportion 46 is terminated by an end portion 47 which is bent upwards tothe same side as the fixture 45 so as to form a trough-like shape inwhich portion 46 comprises the base. The fixture 45 and end portion 47have flanges which form grooves located side by side, also outer grooves50 and 51 located at the free sides of the end portion 47 and fixture45, also internal grooves 48 and 49 at a distance from the said sides.Furthermore there are four sections of screwed tube 52 at the outer"corners" which limit the trough shape formed by the fixture 45 andportions 46, 47. These screwed tubes 52 are extended strips with holes,in the ends of which self-tapping screws can be inserted as will bedescribed later. As assumed previously, the slats are made from anextruded aluminium profile and screwed tube of this type can easily beinserted during manufacture.

As shown in FIG. 6 the grooves 50 and 51 are intended to support a glassor other transparent disc 53 which extends across the aperture of thesaid trough shape which has been formed. Here the groove 50 is providedwith an outer flange across which the glass can be snapped into positionduring assembly by pressing the groove 51 against the resilient actionof a rubber section 54. By this means a closed space is formed.

A metal unit 64 which is designed to utilise the solar heat is insertedin grooves 48, 49. The unit 64, which should preferably be made fromextruded light metal, includes an extended plane portion 65 the ends ofwhich are located in grooves to insulating strips 66, which in turn aresupported by grooves 48,49 and which thus join element 64 to the slats.Furthermore unit 64 contains a portion 67 in the form of a tube, whichin the embodiment illustrated in FIG. 6 is located in the centre ofportion 65.

The invention is that the sun rays which pass through the glass 53should impinge on the large surface of portion 65 and heat this up. Thisheat is transmitted by conduction to portion 67, the side of whichfacing the glass 53 is also obviously heated up. A heat-absorbingmedium, preferably water, by means of which the solar heat can beutilised should flow in a cavity 68 in portion 67.

To ensure high absorption of the solar radiation the side of unit 64which faces the glass 53 should be provided with an absorbent coating,e.g. dark oxidation. The absorption of solar heat can be regulated bythe shaping of the heat absorbing portion, which can be given a shapediffering from that of the tubular portion 67 which is illustrated here.Thus there can be several tubular portions which can easily be obtainedby extrusion and it is alternatively possible to design the aperture forthe heat absorbing medium in the form of an extended chamber which islocated under a major portion of the side facing the glass 53. As shownin FIG. 6 the flow passage 68 can be provide with internal flanges whichwill increase the heat absorption surface for the medium.

To insulate the heated unit 64 to prevent cooling down on the side whichis not subjected to solar radiation a layer of insulation 69 is laidagainst the side which faces away from glass 53 and this fills the spacebetween unit 64 and portion 46 which forms a base in the trough-likeshape. As mentioned the strips 66 have an insulating function and reduceheat conduction from unit 64 to the rest of the slats.

FIG. 7 shows the ends of two abutting sections 44. These are providedwith end plates 56 which at these ends seal the space 58 (FIG. 6) formedin the glass 53. The end plates are attached by means of bolts which arethreaded into the screwed pipes 52. The diagram also shows that thetubular portion 67 is drilled so that the flanges 49 are removed at oneend portion. In this drilled aperture one slat is provided with a thread62 whilst the other slat has a smooth bore 59. The threaded end of anipple 60 is inserted with a seal into the thread, and the other end isprovided with a sealing ring 61 which provides a seal in the smooth bore59. Thus these slats can move relative to each other, which would beimpossible if the nipple were threaded into both slats. Alternativelythe nipple can be made fully "floating", i.e. with sealing rings at bothends.

If the desire is to design a sun screen installation as solarinterceptor the slats 44 are inserted instead of slats 24 to the desiredextent, bearing in mind the temperature rise capacity. Consecutive slatsare connected together with nipples 60 as shown in FIG. 7. At their farends the outer slats are connected to piping in which a fluid,preferably water plus antifreeze, is supplied to or withdrawn from theslats in such a way that each slat is traversed in the tubular portion67 by the fluid. When there is solar radiation the rays of the sunpenetrate the glass 53 and impinge on the upward facing side of portion65 which as already mentioned is provided with an absorbent coating. Asa result the material in the slat is heated up. As a result of the flowof the fluid heat is extracted and thus heat conduction takes place toportion 67. By means of the flanges shown the material makes goodcontact with the fluid and heat transfer is good. By this means thetemperature rise effect can be utilised. The short-wave rays of the suncan penetrate the glass 53 with only slight losses. When they impinge onthe inner surface they are converted to heat and the long-wave thermalradiation which is subsequently reflected mainly towards the inside ofglass 53. By this means the irradiation of energy is much greater thanoutward radiation via the glass 53. Radiation of heat from the rear sideis restricted by the insulating coating 69. Heat transfer to the casingof the slat, the fixture 45 and portions 46, 47 is restricted by theinsulating strip 66.

We claim:
 1. An arrangement of slat screens for solar protection,comprising: a plurality of elongated slats mounted in spacedrelationship to each other on a support and together forming a screenfor intercepting the rays of the sun over a predetermined angular zone,each slat being an extruded light metal piece comprising a wide portionforming a plate, side edge portions extending upwardly from said wideportion on opposite sides thereof so as to form a trough, said edgeportions having an outer ends thereof away from said wide portion firstgrooves, a transparent disc accommodated in said grooves so that aclosed space is formed in the slat into which the rays of the sun maypenetrate through the disc, said side edge portions having secondgrooves closer to said wide portion than said first grooves,thermally-insulating strips in said second grooves, a plate-shaped unitaccommodated in said strips and of extruded light metal, and having atubular portion for flow of fluid for dissipating the heat formed bysolar radiation on the slat to a pipe system for the fluid, said unitdividing the space between the transparent disc and said wide portioninto a first space located between the disc and the unit, and a secondspace located between the unit and said wide portion, and a plate-shapedinsulating body in said second space, said support has slat holders withprojections having surfaces which face away from each other and whichslope in such a way in relation to each other that together they form anentry portion which opens out from ends of the projections, said entryportion terminating inwardly in a groove in each projection, each slatincluding a fixture which has two flanges facing each other and havingouter hook-shaped projections facing each other, the distance betweenthe flanges being such that the hook-shaped projections offer a widenedout entry portion so that upon bending of the flanges they may pass thewidest section of the entry portion, which is wider than the distancebetween the hook-shaped projections, so that after passing the entryportion the hook-shaped projections can snap downwards into said grooveto hold the slat.
 2. An arrangement according to claim 1, comprising anipple arranged between tubular portions of adjacent consecutive slatsand having ends extending into the respective tubular portions of saidconsecutive slats.
 3. An arrangement according to claim 2, wherein saidsupport has a cross sectional profile which is essentially unchangedover its length, said holders comprising short portions of a profilehaving said projections on an angular leg, and another angular leg forattachment to the support by screws for which notches are provided inthe form of longitudinal grooves.
 4. An arrangement according to claim 2or 3, comprising bracket fittings for said support, said bracketfittings having a U-profile with a web to be attached to a structure andwith flanges surrounding the support and fastened thereto.
 5. Anarrangement according to claim 2 or 3, comprising a stay for staying thesupport, the cross-section of said stay having the shape of a T-profile,with a flange removed at end portions thereof so as to form a flushfixture for a web of the T-profile.